Nanostructured K‐Doped ZnO Thin Films: Synthesis and Investigations

The present research describes the optical, structural, dielectric, photocatalytic, and antibacterial characteristics of potassium‐doped ZnO thin films synthesized via sol–gel dip coating technique with a K doping concentration of (1, 2, 3, 4, 5) wt%. Thin films are annealed at optimized temperatures. K‐doped ZnO has a hexagonal wurtzite phase having a preferential orientation along the (101) plane. The size of the crystallite decreases as the potassium doping percentage rises. Optical analysis reveals that the bandgap decreases when the quantity of K doping in ZnO increases. Dielectric constant experiments show that when the K doping % is raised, AC conductivity of thin films rises as well. Thin film resistivity and Hall coefficient decrease with increasing K concentration, but conductivity, mobility, and carrier concentration rise. Gram‐positive and gram‐negative bacteria are both responsive to K‐doped ZnO. With such antibacterial properties, K‐doped ZnO can be used in biomedicine and to protect the environment. The methylene blue dye is effectively degraded by the photocatalyst K‐doped ZnO, making it useful for removing pollution from wastewater.